Subrect snapshot support.

content/browser/renderer_host/compositor_impl_android.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/browser/renderer_host/compositor_impl_android.h"
 
 #include <android/bitmap.h>
 #include <android/native_window_jni.h>
 
 #include "base/bind.h"
@@ skipping 241 matching lines @@
 void CompositorImpl::DeleteTexture(WebKit::WebGLId texture_id) {
   WebKit::WebGraphicsContext3D* context =
       ImageTransportFactoryAndroid::GetInstance()->GetContext3D();
   if (context->isContextLost() || !context->makeContextCurrent())
     return;
   context->deleteTexture(texture_id);
   context->shallowFlushCHROMIUM();
   DCHECK(context->getError() == GL_NO_ERROR);
 }
 
-void CompositorImpl::CopyTextureToBitmap(WebKit::WebGLId texture_id,
+bool CompositorImpl::CopyTextureToBitmap(WebKit::WebGLId texture_id,
                                          gfx::JavaBitmap& bitmap) {
+  return CopyTextureToBitmap(texture_id, gfx::Rect(bitmap.size()), bitmap);
+}
+
+bool CompositorImpl::CopyTextureToBitmap(WebKit::WebGLId texture_id,
+                                         const gfx::Rect& sub_rect,
+                                         gfx::JavaBitmap& bitmap) {
+  // The sub_rect should match the bitmap size.
+  DCHECK(bitmap.size() == sub_rect.size());
+  if (bitmap.size() != sub_rect.size() || texture_id == 0) return false;

[no sievers, 2012/12/18 19:33:19]

line break before return
I guess the dcheck() can go away now

+
   GLHelper* helper = ImageTransportFactoryAndroid::GetInstance()->GetGLHelper();
   helper->ReadbackTextureSync(texture_id,
-                              bitmap.size(),
+                              sub_rect,
                               static_cast<unsigned char*> (bitmap.pixels()));
+  return true;
 }
 
 void CompositorImpl::animate(double monotonicFrameBeginTime) {
 }
 
 void CompositorImpl::layout() {
 }
 
 void CompositorImpl::applyScrollAndScale(gfx::Vector2d scrollDelta,
                                          float pageScale) {
@@ skipping 119 matching lines @@
     case ANDROID_BITMAP_FORMAT_RGBA_8888:
       return GL_UNSIGNED_BYTE;
       break;
     case ANDROID_BITMAP_FORMAT_RGB_565:
     default:
       return GL_UNSIGNED_SHORT_5_6_5;
   }
 }
 
 } // namespace content